do you know how can i sell my fashion collection through other web sites selling directly to costumers (intermediaries or final consumers)
Do you mean that you would like to start up an affiliate program, where you can have others (website owners) promote your products in exchange for a commission?
use ebay and add a affilate to your website
Huh? I'm confused.
she can sell her fashion items on ebay to her customers, make a ebay store.
Also she could add a affilate script to her website if she has one.
Try to register yourself in directories which Drop-shipper buy to become one for you.
Drop-shippers would contact you and would sell your products for a %. You will be doing the actual shipping.
Affiliate marketing is one of the way to promote your product, you may also need experimental marketing targeting specific customers depend on your products. Also note the latest trend is key for such products.
You might want to check out clickbank.com . The fees are prettyhigh, but you can offer anyone with an account an affiliate link to sell your product with a % commission on the sale at whatever % you set.